Crown-pin.



F. J. STARR.

GROWN PIN.

APPLICATION rum) MAY 12, 1909.

Patented Feb. 21, 1911.

UNITED STATES PATENT OFFICE.

FREDERICK JAMES STARR, OF ASBURY PARK, NEW JERSEY, ASSIGNOR TO CONSOLI- DATED DENTAL MANUFACTURING COMPANY, OF NEW YORK, N. Y., A CORPORA- TION OF NEW YORK.

CROWN-PIN.

Specification of Letters Patent.

Application filed May 12, 1909.

To all whom it may concern:

Be it known that I, FREDERICK JAMES STARR, a citizen of the United States, and resident of Asbury Park, in the county of Monmouth and State of New Jersey, have invented a new and useful Crown-Pin, of which the following is a specification.

My invention relates to a crown pin for use in dentistry, the object being to provide a pin offset from the center of its base so that the pin may occupy a position substantially in the vertical central line of the tooth crown while its base may occupy the natural position of the root cavity, thereby retaining the full strength of the root as a primary support and at the same time embedding the pin where it will support the crown to the best advantage.

In the accompanying drawings, Figure 1 is a vertical section through a tooth crown, showing the pin seated therein, Fig. 2 is a view of the crown pin in elevation, Fig. 3 is a similar view taken at an angle of 90 to the view Fig. 2, Fig. 4 is an end or plan View, and Fig. 5 is an opposite end or plan view.

The tooth crown is denoted by 1. The portion of the crown pin which is to be embedded in the tooth crown is denoted by 2 and is flattened on one side asshown at 3, to prevent axial displacement of the crown 1 relatively to the pin and is further provided with riffles 4: to coact with the body of cement 5 to secure the crown to the pin. The root prong of the pin is denoted by 6, and it is also provided with a flattened side 7 and its surface is broken in the present instance by grooves 8, to coact with the cement, not shown, employed to fasten it in the root cavity.

Intermediate of the crown and root prongs 3 and 6, there is a flattened base 9, the crown prong 3 being preferably located at and emanating from the central portion of said base, while the root prong 6 is offset from said center and extends from the base in a direction opposite that from which the crown prong extends.

The crown and root prongs and flattened base may be formed in one integral piece, and by keepin on hand pins having the root prongs ofl set to diflerent extents, for

instance, two or three different extents, sub

stantially all the varying eccentricities of root cavities may be accommodated without cutting away the root of the tooth beyond what is necessary to accommodate the root prong. Furthermore, the flattened base provides for seating the crown and root firmly in position where no tilting strain will be exerted on the root prong when pressure is exerted on the crown as in masticating food.

What I claim is:

A crown pin havin the crown prong and a single root prong oflset laterally one from the other and united by a flat base which projects laterally beyond the bodies of the prongs.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses, this thirtieth day of April 1909.

FREDERICK JAMES STARR.

l/Vitnesses:

SARAH J. VAN GELDER, GEORGE W. VAN GELDER. 

